UNSATURATED alpha -HYDROPERFLUOROALKYLSULFONYL FLUORIDES

ABSTRACT

New compounds CF2 CF(CFR)nCFHSO2F wherein R is F or perfluoroalkyl containing one to five carbon atoms and n is an integer of 1 to 5, are prepared by reacting SO3 with the corresponding fluorocarbon diolefin to form a sultone, reacting the sultone with water, followed by decarboxylation. The compounds of this invention are useful as comonomers with tetrafluoroethylene, in the preparation of stable polymers with ion exchange capabilities.

Uilltd States Patent 11 1 [11] 3,714,245

Beckerbauer 1 Jan. 30, 1973 1 UNSATURATED a-HYDROPER- 3,282,875 11/1966 Connolly ..260/543 F FLUOROALKYLSULFONYL 3,492,348 l/l970 Boudakian et a]. ..260/543 F FLUORIDES Primary ExammerLorra1ne A. Wemberger [75] Inventor: Richard Beckerbauer, New Castle, Assistant Examiner Richard Kelly Att0rneyEdwin Tocker [73] Assignee: E. I. du Pont de Nemours and Company, Wilmington, Del. [57] ABSTRACT 22 i d; Sept 25 1970 New compounds CF =CF(CFR),.CFHSO F wherein R is F or perfluoroalkyl containing one to five carbon [2]] Appl 75693 atoms and n is an integer of l to 5, are prepared by 52 us. c1. ..260/543 F, 260/875, 260/327 s, reacting 3 with the corresponding fluorocarbon 2 0 544 F diolefin to form a sultone, reacting the sultone with [51] Int. Cl ..C07c 143/70 Water, followed y decarboxylatioh- The Compounds [58] Field of Search ..260/543 F of this invention are useful as oomonomors with tetrafluoroethylene, in the preparation of stable 5 R f re Ci d polymers with ion exchange capabilities.

UNITED STATES PATENTS 3,041,317 6/1962 Gibbs et al. ..260/543 F 2 Claims, No Drawings UNSATURATED a- HYDROPERFLUOROALKYLSULFONYL FLUORIDES This invention relates to new fluorocarbon vinyl sulfonyl fluorides.

Fluorocarbon vinyl sulfonyl fluorides have been disclosed in US. Pat. Nos. 3,282,875 to Connolly and Gresham and 3,041,317 to Gibbs and Griffin; and in Dutch Pat. Publication 12232/67.

The present invention provides a new series of fluorocarbon vinyl sulfonyl fluorides represented by the formula wherein R is F or perfluoroalkyl containing from one to five carbon atoms and n is an integer of 1 to 5. These compounds may also be referred to as unsaturated ahydroperfluoroalkyl sulfonyl fluorides.

The compounds of this invention include: CF =CF-CF CFHSO F CF =CFCF CF CFHSO F CF =CFCF CF CF,CF CFHSO F CF =CFCF(CF )CF CFHSO F CF =CFCF(C F )CF CFHSO F CF CFCF CF(CF )CF(CF )CF CFHSO F The general procedure for preparing compounds of this invention is to react SO with the diolefm compound CF =CF(CFR),,CF=CF wherein R and n have the same meaning as hereinbefore described to convert one of the olefin groups to the sultone followed by reaction of the sultone with water to convert the sultone group to followed by decarboxylation in water to give the compound CF =CF(CFR),,-CFHSO F.

The reaction of the diolefin with 80;, is carried out at molar ratios of diolefin/S of 2 or greater to minimize reactions at both double bonds.

Alternately, one of the double bonds of the diolefin compound can be blocked (e.g., by halogenation) prior to reaction with S0, and subsequent reactions and the desired product formed by regeneration of the double bond. This is the preferred method for preparing the compound CF =CFCF CFHSO F of this invention.

The compounds of the present invention are colorless liquids boiling above 80 C. and with density greater than 1.5 g./ml. f

The compounds of this invention are useful as comonomers with tetrafluoroethylene to prepare stable fluorocarbon polymers containing SO F groups. These --SO F groups can be converted into strong acid groups by hydrolysis resulting in copolymers with ion exchange properties. Copolymerization with tetrafluoroethylene can be carried out in the manner described in US. Pat. No. 2,946,763 to Bro and Sandt, especially Example 4 thereof. Conversion of the SO 1 groups in the resultant copolymer to other functional groups including the SO H group can be done by the procedures disclosed in U.S. Pat. No. 3,282,875 to Connolly and Graham.

The following examples are intended to be illustrative of the present invention and not as a limitation thereof (parts and percents are by weight unless otherwise indicated):

EXAMPLE l lnto a dry flask wasdistilled 92 g. of 4,5-dichloro-octofluoropentene-l (b.p. 92 C.) and 40 g. of sulfur trioxide. The mixture was refluxed for 20 hours; the temperature rose from 40 to 54 C. Excess S0, was distilled out, followed by 109 g. of the sultone (b.p. 55l25 mm; vapor phase chromatography retention time relative to air 13.8 on a 20 footX '74 inch dia. 20 percent Fluorolube S30 (liquid polymer of chlorotrifluoroethylene) on Chromosorb column at C., He flow 100 m1./min.). F N.M.R. spectrum supports the structure with chemical shifts (in ppm. from CFC1 as listed 7 The IR. spectrum has a strong peak at 1,440 cm (sultone) and no absorption from 1,440 to 4,000 cm". This sultone product (91 g.) was stirred with 100 ml. of water until CO evolution stopped (4 hours). The lower layer was separated dried and distilled to give 73.2 g. of the a-hydrosylfonyl fluoride, (b.p. 158 vapor phase chromatography relative retention time 15.1). Chemical shifts of F N.M.R. spectrum are:

CF Cl CFC1 CF CFH SO F Proton N.M.R. shows one CFH- group. The LR.

spectrum has a strong band at 1,460 cm (SO F) and a weak absorption at 3,000 cm (C-H).

This product (10 g.) was refluxed with 4 g. of zinc dust in 50 ml. of dioxane for 2 hours, filtered and added to a dilute aqueous HCI solution. The lower layer was separated and washed 3 times to yield the unsaturated a-hydrosulfonyl fluoride (b.p. 90 est., vapor phase chromatography relative retention 7 time 3.24). Chemical shifts from F N.M.R. are

CF CF CF CFH SO F EXAMPLE 2 sorption at 1,440 cm (CF, CF'-) and no absorption near 3,000 cm (C-H). This product was stirred in water at 60 for 1 hour, evolution of CO, ceased and the lower layer was removed and dried. Vapor phase chromatography showed complete conversion to the est.). The IR. spectrum had strong bands at 1,455 cm" '(SO F) and 1,783 cm (CF CF--) and a weaker bank at 3,000 cm- (-Cl-l). By starting with the corresponding diolefin, this procedure can be used to prepare the remaining compounds of this invention wherein n is 3, 4 and 5.

The starting diolefins can be prepared by the processes disclosed inthe following articles: Cesium Fluoride Catalyzed Rearrangement of Perfluorodienes to Perfluorodialkylacetylenes" J. Am. Chem. Soc. 83 1767 (1961 Preferential Replacement Reactions of Highly Fluorinated Alkyl Halides. 11 Some Reactions of Fluorinated Allyl iodides, J. Am. Chem. Soc. 79 4170 (1957); .l. E. Fearn and L. A. Wall, fPreparation and Polymerization of Some Perfluorodienes," National Bureau of-Standards Report (April, 1964); and J. E. Fearn and 'L. A. Wall, Polymers of Perfluorohexadiene, Perfluoroheptadiene, and Perfluorooctadiene, National Bureau of Standards Report 8623 (February, 1965 As many widely different embodiments of this invention may be made without departing from the-spirit and scope thereof, it is to be understood that this invention is not limited to these specific embodiments thereof except as defined in the appended claims.

What is claimed is:

1. Compounds of the formula 

1. Compounds of the formula CF2 CF(CFR)nCFHSO2F wherein R is F or perfluoroalkyl containing from one to five carbon atoms and n is an integer of 1 to
 5. 